Method of treating synthetic polyamidic and polyester yarns



United States Patent METHOD OF TREATING SYNTHETIC POLY- AMlDIC AND POLYESTERYARNS George W. Brooks, Belmont, N. C., assignor to Belmont Throwing Company, Belmont, N. C., a corporation of North Carolina No Drawing. Application May 15, 1953, Serial No. 355,405

The terminal portion of the term of the patent subsequent to June 1, 1971, has been disclaimed Claims. (Cl. 57-156) 2,725,714 Patented Dec. 6, 1955 ice - forty to one hundred denier yarn is only twisted as high This invention relates to a method of super-twisting and dyeing synthetic polyamidic and polyester filament yarns.

This method may be used with various types of polyamidic and polyester yarns which are capable of being set by heat such as nylon, which is a synthetic linear condensation polyamide, or a synthetic polymeric amide yarn, and Dacron, which is a synthetic linear condensation polyester yarn.

Heretofore, such yarns have been treated to give the same a wool-like effect by increasing the elasticity or curliness of the yarn by means of imparting a super-twist to the yarns. Such prior processes are disclosed in Patents Nos. 2,019,183 and 2,019,185, 2,564,245 and 2,585,- 518. This prior process is known as the Helanca process, or the super-twisting process. According to this prior process, artificial yarns are provided with increased elasticity and curliness by imparting a high number of twists to the yarn, setting the twist and thereafter, untwisting the yarn. Such yarn has been used in various types of fabric to provide elasticity thereto.

However, due to. the thermoplastic nature of artificial yarns of this type, it has heretofore been impossible to dye the yarns while in the yarn state as the increased temperatures necessary in the dyeing processes would take out or unset the elasticity or curliness which had heretofore been placed in the super-twisted yarn. For this reason, the use of super-twisted polyamidic or polyester yarns has been limited to articles which could be dyed after being knitted or woven and, in which instance, the article of necessity had to be a solid color.

It is, therefore, the primary object of this invention to provide a super-twist yarn and method of making the same, wherein the super-twisted yarns are dyed during the super-twisting process so that the individual yarns may be dyed before being formed into an article. In this way, super-twisted yarns made according to this process, may be used in a variety of colors to produce pattern effects in the finished articles, which pattern effects will still have the elasticity and curliness which is' desired.

In accordance with said process, one multi-filament strand of the polyamidic or polyester yarn is twisted a plurality of turns in one direction, after which the yarn is pre-set, then the yarn is dyed under the necessary high temperature and pressure, then additional twists in the same direction, are imparted to the yarn, then the yarn is again set after which it is pro-shrunk. Then, if desired, additional twists maybe imparted to the yarn in the same direction up to the total number of turns or twists desired. If additional twists are added, the yarn is then set and dried- The yarn is then untwisted or twisted. in a reverse direction back to the point zero, or beyond. A strand of yarn, thus treated, is then plied or twisted with a yarn treated in a similar manner, but twisted in the opposite direction and the yarn, thus treated, may be formed into various types of articles, as desired, and further dyeing or processing is not necessary.

as fifty turns. If heavier than one hundred denier yarn is used according to this process, the amount of twist imparted thereto should be somewhat less than fifty turns.

The invention is not limited to any particular type of dye. and the whole range of dyes having aflinity for the particular polyamide or polyester being twisted, may be used. For example, in treating nylon according to this process, the following dyes are suitable:

. Anthraquinone Green, GW, Color Index 1078;

. Anthraquinone Blue, RXO, Color Index 1076;

. Dupont Milling Yellow, S-G, Color Index 642;

. Dupont Milling Orange, RTR 152 (No Color Index or Prototype No.);

. Dupont Milling Red, SWB, Color Index 430;

. Dupont Neutral Grey, GL (No Color Index or Prototype No.);

7. Dupont Neutral Brown, BGL (No Color Index or Prototype No.).

Now, it is well known that nylon can be dyed with almost any type of dye and the above examples are listed by way of illustration only.

Various indigoid types of dyes are suitable for dyeing Dacron, as well as nylon. For example:

. Indanthrene Red Violet RH, Color Index 1212;

. Helidone Pink R. Ex., Prototype 109;

. Indanthrene Brown, RRD, Prototype 121;

. Vat Khaki GP Powder, Indigo M. L/4B, Color Index Indigo ML/2B, Color Index 1183;

. Helidone Rx, Color Index 1217;

. Indigo Yellow G (Ciba), Color Index 1196;.

. Sulfanthrene Black PG, Double Paste Dupont.

Also, various acetate dyes will produce good results on nylon, and Dacron.

For example:

1. Acetamine Yellow N (No Prototype or Color Index 2. Orange GR Concentrate, Prototype 43;

3; Cibacete Red, 3B, Prototype 61;

4. Celliton Blue FFR, Prototype 228;

5. Celliton Fast Yellow G, Prototype 242;

6. Celliton Fast Rubine 3B, Prototype 239.

Also, various vat pigments, neutral, chrome, direct and acid colors may be utilized according to well known processes in practicing this invention.

Example One 70 denier multi-filament (34 ends) nylon yarn is twisted twenty-five turns per inch to the right. This is done in a conventional twisting machine and then the yarn is removed and is subjected to a pre-setting treatment which comprises subjecting the yarn to steam for three periods of approximately one and one-half hours each. The yarn isthen rewound on perforated metal dye tubes and is dyed at temperatures between degrees and 300 degrees Fahrenheit preferably around 240 to 265 degrees Fahrenheit and under super-atmospheric pressure. The yarn is dried after the dyeing operation and is rewound onto bobbins and an additional 25 turns of twist per inch are imparted thereto to the right, or the same direction in which the first turns of twist were imparted.

The yarn is then given a second setting by subjecting the same to steam for three periods of approximately one and one-half hours each. The yarn on the bobbins is then placed in a preboarding machine and is subjected to wet steam or water for a period of approximately one hour at temperatures from 250 degrees Fahrenheit to 270 degrees Fahrenheit at pressure of from 22 to 28 pounds. This is a pre-shrinking or shrinking operation which causes the yarn to shrink. The yarn is then dried at a temperature of from 150 degrees Fahrenheit to 170 degrees Fahrenheit for a period'of 12 hours, or until dry. After the yarn is dry, any additional twist which is desired is added to the right, or in the same direction up to a total number of turns of twist approximating 100 turns per inch depending upon the denier. In using 70 denier yarn, no additional twist is necessary.

After the final twist has been imparted to the yarn, the yarn is set an additional time by subjecting the same to steam for three periods approximating one and onehalf hours each. The yarn is then twisted in the opposite direction, or untwisted with the total number of turns which have been imparted thereto. In this instance, the yarn is twisted back to the left up to 100 turns per inch, or to the point zero. If desired, the twist may go back slightly beyond the point zero to give some additional twist to the yarn.

A second 70 denier, multi-filament nylon yarn is treated in an identical manner, except that the twist imparted thereto is to the left or opposite to the direction in which the twist is imparted to the first nylon yarn. These two yarns are then twisted or plyed together at approximately two turns per inch to form a single multi-ply strand and the yarn thus formed may be knitted or woven into articles of various types and no additional dyeing or treating is necessary.

The above example may be followed in treating other polyamidic or polyester yarns in accordance with this invention and it should be noted that the number of turns of twist may be varied in accordance with the denier of the yarn and the desired elasticity or curliness.

In imparting the initial twist, it is desirable to impart between 20 and 30 turns per inch, preferably 25 turns. In the second twisting operation, it is again desirable to impart 20 to 30 turns per inch in the same direction, preferably 25 turns. In the case of yarns of greater than 40 denier, after the total of 50 turns has been imparted thereto, the twist is locked and pre-shrunk and dried and no additional twist is added thereto before backing out or untwisting the yarn a like number of turns.

Where it is desired to impart a total number of turns greater than 50, such as in yarn of between 20 and 40 denier, after the second twisting process and after the preboarding and drying, the additional twist is added thereto after which, the yarn is set and then untwisted as above set forth.

After presetting or first steaming operation, the yarn is preferably wound on perforated metal dye tubes in order to facilitate the dyeing thereof.

In the steaming operations used in pre-setting the yarn and in the additional pre-setting processes, the yarn in loose condition is subjected to steam for a period of approximately one and one-half hours, after which there is a short lag period, during which time the yarn will tend to dry out and then it is again subjected to steam for two additional periods approximating one and one-half hours each with a lag period therebetween. This setting is preferably done in a regular conditioning box or twist setter, such as the H. W. Conditioner manufactured by Industrial Drier Corporation.

The pre-shrinking operation under high temperature, shrinks yarn and the yarn on collapsible bobbins is placed in a conventional preboarding machine and is subjected to wet steam or water. The pie-shrinking time is preferably one hour at 265 degrees Fahrenheit and 25 pounds pressure for nylon, but may vary between 250 degrees Fahrenheit and 270 degrees and the pressure may vary between 22 and 28 pounds. If desired, the yarn may be in loose form when pre-shrunk.

In the drying operation, which is subsequent to the preshrinking operation, only dry heat is used which is preferably accomplished by placing the yarns in a drying room equipped with a heater and an exhaust fan. Apparently, approximately 12 hours is the minimum time necessary to dry the yarns, but a different amount of time, more or less, is not harmful provided the yarn is thoroughly dried. The preferred temperature is degrees Fahrenheit for nylon and Dacron and may range betwen 150 degrees and degrees Fahrenheit.

It is thus seen that I have provided means for treating polyamidic and polyester filament yarns which comprises partially twisting said yarns, then dyeing the yarns, and additionally twisting the yarns so that the resultant yarns will have a supertwist to provide maximum elasticity and curliness' and whereby the super-twisted yarns are dyed in yarn form without destroying the set or elasticity thereof.

The new yarn resulting from this invention has a wide variety of uses. For example, yarns of one or more colors, may be used in forming patterned fabric, such as argyle socks or heels of ladiesstockings which will have the desired characteristics of stretchability and curliness. Various effects may be obtained by applying one end of a yarn treated according to this process and dyed one color, together with another yarn treated according to this process and dyed a second color to give a multi-color, or multi-ply yarn, which may be utilized to give a wide variety of effects in the finished product.

In the drawings and specification, there has been set forth a preferred embodiment of the invention and, although specific terms are employed, they are used in a generic and descriptive sense only, and not for purposes of limitation, the scope of the invention being defined in the claims.

I claim:

1. That method of treating multi-filament yarns of the class consisting of polyamidic and polyester yarn of from 20 to 100 denier which comprises twisting the yarn at least 5 turns per inch in one direction, heat setting the twisted yarn to stabilize it against subsequent processing, dyeing the twisted and set yarn, twisting the yarn an additional plurality of turns per inch in the same direction as before to provide a total twist of from 40 to 100 turns per inch, then heat setting and shrinking the twisted and set yarn, and then untwisting the yarn a number of turns per inch approximating the total number of turns per inch which has previously been applied thereto.

2. That method of treating multi-filament yarns of the class consisting of polyamidic and polyester yarns of from 20 to 100 denier which comprises twisting one yarn at least 5 turns per inch in one direction, heat setting the twisted yarn to stabilize it against subsequent processing, dyeing the twisted and set yarn, twisting the yarn an additional plurality of turns per inch in the same direction to provide a total twist of from 40 to 100 turns per inch, heat setting and shrinking the yarn, and untwisting the yarn to substantially Zero twist, then repeating the above operation on a second yarn by applying reverse twist thereto, and then twisting the two yarns together.

3. That method of treating multi-filament yarns of the class consisting of polyamidic and polyester yarns of from 20 to 100 denier which comprises imparting from 20 to 30 turns of twist per inch to the yarn in one direction, heat setting the twisted yarn to stabilize it against subsequent processing, dyeing the twisted and set yarn, imparting 20 to 30 turns of additional twist per inch thereto in the same direction as before, heat setting and then shrinking the yarn, then imparting additional turns of twist thereto in the same direction as before to provide a total twist not exceeding 100 turns per inch, heat setting the yarn, then untwisting the yarn a number of turns substantially equal to the total number of turns imparted thereto.

4. That method of treating multi-filanient yarns of the class consisting of polyamidic and polyester yarns of from 20 to 100 denier which comprises imparting from 20 to 30 turns of twist per inch thereto in one direction to a first yarn, heat setting the twisted yarn to stabilize it against subsequent processing, dyeing the twisted and set yarn, imparting 20 to 30 turns of additional twist per inch thereto in the same direction as before, heat setting and then relaxing and shrinking the yarn, then imparting additional turns of twist thereto in the same direction as before to provide a total twist not exceeding 100 turns per inch, heat setting the yarn, then untwisting the yarn a number of turns substantially equal to the total number of turns imparted thereto, then treating a second yarn as above outlined but imparting the twists in the opposite direction from that imparted to the first yarn, and then plying the two yarns together at a relatively low twist.

5. That method of treating multi-filament yarns of the class consisting of polyamidic and polyester yarn of from 20 to 100 denier which comprises twisting the yarn at least 5 turns per inch in one direction, heat setting the twisted yarn to stabilize it against subsequent processing, dyeing the twisted and set yarn at a temperature between 180 and 300 F. under superatmospheric pressure to color and additionally set the yarn, twisting the yarn an additional plurality of turns per inch in the same direction as before to provide a total twist of from 40 to 100 turns per inch, then heat setting, relaxing and shrinking the yarn, and then untwisting the yarn a number of turns per inch approximating the total number of turns per inch which has previously been applied thereto.

6. That method of treating multi-filament yarns of the class consisting of polyamidic and polyester yarns of from 20 to 100 denier which comprises twisting one yarn at least 5 turns per inch in one direction, heat setting the yarn to stabilize it against subsequent processing, dyeing the twisted and set yarn at a temperature between 180 and 300 F. under superatmospheric pressure which additionally sets the yarn, twisting the yarn an additional plurality of turns per inch in the same direction as before to provide a total twist of from 40 to 100 turns per inch, then heat setting and shrinking the yarn, then untwisting the yarn a number of turns per inch approximating the total number of turns per inch which has previously been applied thereto, then repeating the operation on a second yarn but twisting the second yarn in the opposite direction, and then plying the two yarns together at a relatively low twist.

7. That method of supertwisting and dyeing artificial multi-filament yarns of the class consisting of polyamidic and polyester yarn of from 20 to 100 denier which comprises imparting from 20 to 30 turns per inch of twist to the yarn in one direction, heat setting the yarn to stabilize it against subsequent processing, dyeing the twisted and set yarn at a temperature between 180 and 300 F. and at superatmospheric pressure, imparting additional twist of 20 to 30 turns per inch to said yarn in the same direction, heat setting the yarn, supporting the yarn loosely in a wet heated atmosphere for a sufi1- cient time to cause the yarn to shrink, drying the yarn and untwisting the same to substantially zero twist.

8. That method of supertwisting and dyeing artificial multi-filament yarns of the class consisting of polyamidic and polyester yarns of from 20 to denier which comprises imparting from 20 to 30 turns per inch of twist to one yarn in one direction, heat setting the yarn to stabilize it against subsequent processing, dyeing the twisted and set yarn at a temperature between and 300 F. and at superatmospheric pressure, imparting additional twist of 20 to 30 turns per inch to said yarn in the same direction, heat setting the yarn, supporting the yarn loosely in a wet heated atmosphere to cause the yarn to shrink, drying the yarn and untwisting the same to substantially zero twist, then repeating the above operations on a second yarn but giving the same a reverse twist, and then twisting the two yarns together.

9. A method for producing yarns of the class consisting of polyamidic and polyester yarns having highly stretchable characteristics and color fastness which consists in highly twisting one yarn, heat setting said yarn to stabilize it against subsequent processing, dyeing said twisted and set yarn at a temperature of from 180 to 300 F. and at superatmospheric pressure, additionally highly twisting said yarn, heat setting the additional twist in said yarn, shrinking said yarn and then back twisting the yarn to substantially zero twist, then treating a second yarn in a like manner but twisting the second yarn in an opposite direction, and then plying the two yarns together at a relatively low twist.

10. A process of treating synthetic multi-filament yarns of the class consisting of polyamidic and polyester yarns consisting in separately supertwisting two of said multifilament yarns in opposite directions, subjecting the twisted yarns to heat to set the same, dyeing said twisted and set yarns at a temperature between 180 and 300 F. and at superatmospheric pressure which additionally sets the yarns, further supertwisting the yarns in their respective original directions, again subjecting them to heat to set the additional twist in the same, shrinking said yarns, untwisting the two yarns to a substantially zero twist, and twisting the two yarns together in a relatively low twist, thereby producing a multiple strand dyed yarn with latent crimp efiecting physical properties.

References Cited in the file of this patent UNITED STATES PATENTS 1,008,613 Palmer Nov. 14, 1911 1,959,723 Lejeune May 22, 1934 2,019,183 Heberlein Oct. 29, 1935 2,019,185 Kagi Oct. 29, 1935 2,025,175 Pearsall Dec. 24, 1935 2,058,427 Dreyfus et al Oct. 27, 1936 2,089,192 Dreyfus Aug. 10, 1937 2,133,435 Dickie Oct. 18, 1938 2,304,089 Heberlein Dec. 8, 1942. 2,464,433 Carden Mar. 15, 1949 2,504,523 Harris et al Apr. 18, 1950 2,564,245 Billion Aug. 14, 1951 2,585,518 Valentin Feb. 12, 1952 

1. THAT METHOD OF TREATING MULTI-FILAMENT YARNS OF THE CLASS CONSISTING OF POLYAMIDIC AND POLYESTER YARN OF FROM 20 TO 100 DENIER WHICH COMPRISES TWISTING THE YARN AT LEAST 5 TURNS PER INCH IN ONE DIRECTION, HEAT SETTING THE TWISTED YARN TO STABLIZE IT AGAINST SUBSEQUENT PROCESSING, DYEING THE TWISTED AND SET YARN, TWISTING THE YARN AN ADDITIONAL PLURALITY OF TURNS PER INCH IN THE SAME DIRECTION AS BEFORE TO PROVIDE A TOTAL TWIST OF FROM 40 TO 100 TURNS PER INCH, THEN HEAT SETTING AND SHRINKING THE TWISTED AND SET YARN, AND THEN UNTWISTING THE YARN A NUMBER OF TURNS PER INCH APPROXIMATING THE TOTAL NUMBER OF TURNS PER INCH WHICH HAS PREVIOUSLY BEEN APPLIED THERETO. 